If you don't want it to be used in certain situations why not spell it out in the license up front?
A license is a contract, whatever terms and conditions you spell out go as long as they are legal in contract law, no slavery, racism or other protected class discrimination.
As an example of other projects that do this here is a project (GPU grid processing for gnutella) that put a no military use clause in their license.
GPU is a Gnutella client that allows users to share CPU-resources... (which is under GPL and targets only peaceful goals btw).
http://archive09.linux.com/articles/56426 - an interview with the devs where it gives a bit of their license:
Tiziano Mengotti and Rene Tegel are the lead developers on the GPU project. Mengotti is the driving force behind the license "patch," which says "the program and its derivative work will neither be modified or executed to harm any human being nor through inaction permit any human being to be harmed."